Cooling Fan problems

Overheating can be caused by many things but when it occurs at low speeds or when idling in traffic it ismost likely that the electrically powered cooling fans aren't working properly.

If you are overheating under these conditions then you most likely have one of four problems:

1. A bad motor. Hotwire it to see if the motor spins.

2. A bad fan motor relay. See if applying 12 volts to the coil of the relay makes the fan spin.

3. A bad driver in the computer that sends power to the fan felay. Turn the air conditioning on - the fan should come on no matter what the engine temperature is.

4. A bad coolant temperature sensor. It sends a signal to the computer to tell it when to turn on when the engine heats above a setpoint.

Message me at BobHewitt@Misterfixit.com

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